Benzimidazole derivatives intended for inhibiting gastric acid secretion are disclosed in numerous patent documents. Among these can be mentioned GB 1 500 043, GB 1 525 958, U.S. Pat. No. 4,182,766, EP 0 005 129, and BE 890 024. Benzimidazole derivatives proposed for use in the treatment or prevention of special gastrointestinal inflammatory diseases are disclosed in EP-A-0 045 200. N-substituted 2-(pyridylalkylenesulfinyl)benzimidazoles are disclosed in EP-A-0 176 308.
For certain pharmaceutical usage forms there is a great need for high water solubility of the compound to be used. For instance, for intravenous and intramuscular injection formulations, the dose is to be dissolved in a small volume of an aqueous medium. This, of course, requires a high aqueous solubility. However, a high aqueous solubility is often a great advantage also in other cases e.g. for oral formulations.
The compounds in the prior art generally have a low water solubility, which does not admit manufacture of such highly concentrated water solution which are needed for intravenous and intramuscular injections. For example the compounds presented in the European patent application, publication no. 0176308, disclosing N-substituted benzimidazole derivatives, have low water solubility and are thus not suitable for the above-mentioned parenteral use.